Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_3/V15NO327.TXT

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Date: Tue, 20 Oct 92 05:00:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #327
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue, 20 Oct 92       Volume 15 : Issue 327

Today's Topics:
                  Aerospace and Commercial Products
                             DCX Status?
                 Info on book (including Nova rocket)
                         Nuclear Power / FAQ
                   Pres Debate & military spending
          Recognizing a Dyson sphere if you saw one (2 msgs)
                       SETI functional grammar
                             Space Photos
                               Sundrive
          V-2's launched at Russia (was Re: V-2 anniversary)

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

Date: 19 Oct 92 11:54:44 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Aerospace and Commercial Products
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Gary Coffman writes:
>
>>Unfortunately, the aerospace industry is ill equipped to operate
>>when separated from the government teat. There's little consumer
>>demand for $800 toilet seats, or $120 million dollar ex-ballistic
>>missiles. The companies don't have a clue how to make $19 Walkmans,
>>or even $2 million dollar sewage treatment plants. Their corporate
>>culture isn't setup to handle such concepts.
>
>    Hmmm.... I think you might be overstating things here a bit
>much.  Most "aerospace" firms are pretty reasonably diversified
>with a variety of commercial products being produced within the
>firm, already.  Maybe I can give some examples with a couple of
>local firms, where I know their products...(This is being done from
>memory, so don't hold me to exact percentages of market shares...)
>
>    Rockwell -- Built the B1, MX 4th Stage, Space Shuttle, and a
>major contractor on space station.  Also a major subcontractor to
>Boeing for commercial aircraft (about $200 M/yr business), builds
>about 60% of the world's supply of modem chips, builds Goss color
>printing presses (those presses used to print color newspapers),
>automobile doors, axles, etc., and is the world's largest
>manufacturer of sunroofs.  About 75 % of their sales is non-
>government.
[deleted]
>    TRW - builds military spacecraft (classified programs), and
>NASA satellites (GRO and TDRS, for example).  They also have a very
>large autoparts business, make about 80% of the worlds auto airbags
>(among others), and have a very profitable credit/data base business
>(TRW creditline).

Rockwell, TRW, and your other examples, other than McD, are *conglomerates*.
In fact TRW is the prototypical conglomerate. They are really groups
of unrelated companies that happen to be owned by the same parent firm.
No doubt Rockwell/Collins will still be in the commercial radio business,
though military sales do dominate that company now since they abandoned
the amateur and broadcast markets. No doubt Rockwell/Goss will still
be in commercial printing, though newspapers are declining. Etc.
The thing I think you are overlooking is that these subsidaries
operate much as they did before they were taken over by Rockwell
or TRW, maintaining separate managements and corportate cultures. The
question is, how will Rockwell's, or TRW's, *space* and *military*
oriented subsidaries do with the loss of government business?
TRW rings and pistons aren't going to subsidize another unit's losses
for long. The history of conglomerates shows that once a cash cow
starts to stagger, the parent firm puts it out of it's misery before
the hemorrhaging spreads to the parent. The Signal Companies relationship
with Ampex is a good case in point, or AMF and Harley Davidson. In the
latter case, if Harley enthusiasts hadn't bought the company back from
the conglomerate, stopped selling junky Italian motorcycles under their
name, and brought production back to America, it would be history, and
Kawasaki would be the only American made motorcycle.


>   The real trick will be to bring over that entrepreneurial talent
>and skill to utilize the engineers and production equipment now
>being used for government programs.   But, at least in these three
>firms I've looked at, there are nuclei of that talent in-house.

But that talent isn't in the subsidaries that need it. Is there
*any* evidence that any of these conglomerates are willing to
sustain the necessary learning curve losses to transform the relevant
units? Or will they just dump them and buy a more profitable company?

>> And, how much of their military capabilities will they preserve
>>for the day when the world heats up again, as it will?
>    This is a question that I don't think the aerospace industry
>should answer.  This a public policy question which will have to
>answered by the next Congress and presidential administration.
>Keeping unused, or little used, military production facilities
>around will cost money.  I don't expect an aerospace firm will keep
>a production line and tooling around with no orders (or expectation
>of orders) on hand.  Maintaining an industrial base will be the
>responsibility of the Congress and Administration -- and it will
>cost money.

You are absolutely right here. My point is that dumping government
contracts to these firms is a political decision that will have
strategic effects on US technical and military leadership. How
much is that worth? If it means we can't reliably project military
power in time of need, it's worth the nation. If it means we surrender
high tech markets to foreign firms, it means the nation's long term
economic health. If it means we save a bunch of money by not keeping
capabilities we no longer need, then it's a good idea. But I seriously
doubt those capabilities will remain unneeded for long. I'm afraid
that we are making the same mistake we made between WWI and WWII, and
between WWII and Korea where we dismantled a capability that we
profoundly regretted losing in short order.

Gary

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

Date: 19 Oct 92 17:43:33 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: DCX Status?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Scott Fisher) writes:

>Q: Why is the DCX designed to take off and land vertically, taking off
>I can perhaps understand, but landing??  What are the advantages?

To answer this I am enclosing a paper written by Henry Spencer as
a technical introduction to some concpets behind SSTO. (He wrote
it for our Congressional Briefing Packet and has our thanks for doing
so).

  Allen


----------------------------------------
(Semi-)Technical Aspects of SSTO

This paper will try to give you some idea of why SSTO makes technical
sense and is a reasonable idea.  We'll concentrate on the overall issues,
trying to give you the right general idea without getting bogged down
in obscure detail.  Be warned that we will oversimplify a bit at times.

Why Is SSTO Challenging?

Getting a one-stage reusable rocket into orbit doesn't look impossible,
but it does look challenging.  Here's why.

The hard part of getting into orbit is not reaching orbital altitude,
but reaching orbital velocity.  Orbital velocity is about 18,000mph.
To this, you have to add something for reaching orbital altitude and for
fighting air resistance along the way, but these complications don't
actually add very much.  The total fuel requirement
is what would be needed to accelerate to 20-21,000mph.

So how much is that?  (If you don't want to know the math, skip to the
next paragraph for the results.)  The "rocket equation" is
desired_velocity = exhaust_velocity * ln(launch_weight / dry_weight),
where "ln" is the natural logarithm.  The exhaust velocity is determined
by choice of fuels and design of engines, but 7,000mph is about right
if you don't use liquid hydrogen, and 10,000mph if you do.

The bottom line is that the launch weight has to be about 20 times the
dry weight (the weight including everything except fuels) if you don't
use liquid hydrogen, and about 8 times the dry weight if you do.  This
sounds like hydrogen would be the obvious choice of fuel, but in practice,
hydrogen has two serious problems.  First, it is extremely bulky,
meaning that hydrogen tanks have to be very big; the Shuttle External
Tank is mostly hydrogen tank, with only the nose containing oxygen.
Second, some of the same properties that make hydrogen do well on the
weight ratio make it difficult to build hydrogen engines with high thrust,
and a rocket *does* need enough thrust to lift off!  Both of these
problems tend to drive up the dry weight, by requiring bigger and heavier
tanks and engines.

So how bad is this?  Well, it's not good.  Even with hydrogen, an SSTO
launcher which weighs (say) 800,000lbs at launch has to be 7/8ths fuel.
We've got 100,000lbs for tanks to hold 700,000lbs of fuel, engines to
lift an 800,000lb vehicle, a heatshield to protect the whole thing on
return, structure to hold it all together at high acceleration... and
quite incidentally, for some payload to make it all worthwhile.  Most
of the dry weight has to go for the vehicle itself; only a small part
of it can be payload.  (That is, the "payload fraction" is quite small.)
To get any payload at all, we need to work hard at making the vehicle
very lightweight.

The big problem here is:  what happens if the vehicle isn't quite as
light as the designer thought it would be?  All rockets, and most aircraft
for that matter, gain weight during development, as optimistic estimates
are replaced by real numbers.  An SSTO vehicle doesn't have much room for
such weight growth, because every extra pound of vehicle means one less
pound for that small payload fraction.  Particularly if we're trying to
build an SSTO vehicle for the first time, there's a high risk that the
actual payload will be smaller than planned.

That is the ultimate reason why nobody has yet built an SSTO space
launcher:  its performance is hard to predict.  Megaprojects like the
Shuttle can't afford unpredictability -- they are so expensive that
they must succeed.  SSTO is better suited to an experimental vehicle,
like the historic "X-planes", to establish that the concept works and
get a good look at how well it performs... but there is no X-launcher
program.

Why Does SSTO Look Feasible Now?

The closest thing to SSTO so far is the Atlas expendable launcher.  The
Atlas, without the Centaur upper stage that is now a standard part of
it, has "1.5" stages:  it drops two of its three engines (but nothing
else) midway up.  Without an upper stage, Atlas can put modest payloads
into orbit:  John Glenn rode into orbit on an Atlas.  The first Atlas
orbital mission was flown late in 1958.  But the step from 1.5 stages
to 1 stage has eluded us since.

Actually, people have been proposing SSTO launchers for many years.
The idea has always looked like it *just might* work.  For example,
the Shuttle program looked at SSTO designs briefly.  Mostly, nobody has
tried an SSTO launcher because everybody was waiting for somebody else
to try it first.

There are a few things that are crucial to success of an SSTO
launcher.  It needs very lightweight structural materials.  It needs
very efficient engines.  It needs a very light heatshield.  And it
needs a way of landing gently that doesn't add much weight.

Materials for structure and heatshield have been improving steadily
over the years.  The NASP program in particular has helped with this.
It now looks fairly certain that an SSTO can be light enough.

Existing engines do look efficient enough for SSTO, provided they can
somehow adapt automatically to the outside air pressure.  The nozzle
of a rocket engine designed to be fired in sea-level air is subtly
different from that of an engine designed for use in space, and an
SSTO engine has to work well in both conditions.  (The technical
buzzword for what's wanted is an "altitude-compensating" nozzle.)
Solutions to this problem actually are not lacking, but nobody has
yet flown one of them.  Probably the simplest one, which has been
tentatively selected for DC-Y, is just a nozzle which telescopes,
so its length can be varied to match outside conditions.  Making
nozzles that telescope is not hard -- many existing rocket nozzles,
like those of the Trident missile, telescope for compact storage --
but nobody has yet flown one that changes length *while firing*.
However, it doesn't look difficult, and there are other approaches
if this one turns out to have problems.

We'll talk about landing methods in more detail later, but this is one
issue that will be resolved pretty soon.  The primary goal of the DC-X
experimental craft is to fly DC-Y's landing maneuvers and prove that
they will work.

So... with materials under control, engines looking feasible, and
landing about to be test-flown, we should be able to build an SSTO
prototype:  DC-Y.  The prototype's performance may not quite match
predictions, but if it works *at all*, it will make all other launchers
obsolete.

Why A Rocket?

As witness the NASP (X-30) program, air-breathing engines do look like
an attractive alternative to rockets.  Much of the weight of fuel in
a rocket is oxygen, and an air-breathing engine gets its oxygen from
the air rather than having to carry it along.  However, on a closer
look, the choice is not so clear-cut.

The biggest problem of using air-breathing engines for spaceflight is
that they simply don't work very well at really high speeds.  An
air-breathing engine tries to accelerate air by heating it.  This works
well at low speed.  Unfortunately, accelerating air that is already
moving at hypersonic speed is difficult, all the more so when it has
to be done by heating air that is already extremely hot.  The problem
only gets worse if the engine has to work over an enormous range of
speeds:  NASP's scramjet engines would start to function at perhaps
Mach 4, but orbital speeds are roughly Mach 25.  Nobody has ever built
an air-breathing engine that can do this... but rockets do it every week.

Air-breathing engines have other problems too.  For one thing, to use
them, one obviously has to fly within the atmosphere.  At truly high
speeds, this means major heating problems due to air friction.  It
also means a lot of drag due to air resistance, adding to the burden
that an air-breathing engine has to overcome.  Rocket-based launchers,
including SSTO, do most of their accelerating in vacuum, away from
these problems.

Perhaps the biggest problem of air-breathing engines for spaceflight
is that they are *heavy*.  The best military jet engines have thrust:weight
ratios of about 8:1.  (This is at low speed; hypersonic scramjets are not
nearly that good.)  The Space Shuttle Main Engine's thrust:weight ratio,
by comparison, is 70:1 (at any speed).  The oxygen in a rocket's tanks
is burned off on the way to orbit, but the engines have to be carried
all the way, and air-breathing engines weigh a lot more.

And what's the payoff?  The X-30, if it is built, and if it works
perfectly, will just be able to get into orbit with a small payload.
This is about the same as SSTO, at ten times the cost.  Where is the
gain from air-breathing engines?

The fact is, rockets are perfectly good engines for a space launcher.
Rockets are light, powerful, well understood, and work fine at any
speed without needing air.  Oxygen may be heavy, but it is cheap (about
five cents a pound) and compact.  Finally, rocket engines are available
off the shelf, while hypersonic air-breathing engines are still research
projects.  Practical space launchers should use rockets, so SSTO does.

Why No Wings?

With light, powerful engines like rockets, there is no need to land
or take off horizontally on a runway, and no particular reason to.
Runway takeoffs and landing are touchy procedures with little room
for error, which is why a student pilot spends much of his time on
them.  Given adequate power, vertical takeoffs and landings are easier.
In particular, a vertical landing is much more tolerant of error than
a horizontal one, because the pilot can always stop, straighten out
a mistake, and then continue.  Harrier pilots confirm this:  their
comment is "it's easier to stop and then land, than to land and then
try to stop".

What if you don't have adequate power?  Then you are in deep trouble
even if your craft takes off and lands horizontally.  As witness the
El Al crash in Amsterdam recently, even airliners often don't survive
major loss of power at low altitude.  To make a safe horizontal landing,
especially in less-than-ideal weather conditions, you *must* have enough
power to abandon a bad landing approach and try again.  Shuttle-style
gliding landings are dangerous, and airline crews go to great lengths
to avoid them; the Shuttle program, with the nation's best test pilots
doing the flying and no effort spared to help them, has already had
one near-crash in its first fifty flights.  Routine access to space
requires powered landings.

If we are going to rely on powered landings, we must make sure that power
will be available.  Airliners do this by having more than one engine,
and being able to fly with one engine out.  SSTO is designed to survive
a single engine failure at the moment of liftoff, and a second failure
later.  Since (at least) 7/8ths of the takeoff weight of SSTO is fuel,
it will be much lighter at landing than at takeoff.  Given good design,
it will have enough power for landing even if several engines fail.
If SSTO has an engine failure soon after liftoff, it will follow much
the same procedure as an airliner:  it will hover to burn off most of
its fuel (this is about as quick as an airliner's fuel dumping), and
then land, with tanks nearly empty to minimize weight and fire hazard.

Note that in an emergency, vertical landing has one major advantage
over horizontal landing:  horizontal landing requires a runway, preferably
a long one with a favorable wind, while a vertical landing just requires
a small flat spot with no combustible materials nearby.  A few years ago,
a Royal Navy Harrier pilot had a major electronics failure and was unable
to return to his carrier.  He made an emergency landing on the deck of a
Spanish container ship.  The Harrier suffered minor damage; any other
aircraft would have been lost, and the pilot would have had to risk
ejection and recovery from the sea.

Given vertical landing and takeoff, is there any other use for wings?
One:  crossrange capability, the ability to steer to one side during
reentry, so as to land at a point that is not below the orbit track.
The Shuttle has quite a large crossrange capability, 1500 miles.
However, if we examine the history of the Shuttle, we find
that this was a requirement imposed by the
military, to make the Shuttle capable of flying some demanding USAF missions.
A civilian space launcher needs a crossrange capability of, at most, a
few hundred miles, to let it make precision landings at convenient times.
This is easily achieved with a wingless craft:  the Apollo spacecraft
could do it.

Finally, wings are a liability in several important ways.  They are heavy.
They are difficult to protect against reentry heat.  And they make the
vehicle much more susceptible to wind gusts during landing and takeoff
(this is a significant limitation on shuttle launches).

SSTO does not need wings, would suffer by carrying them, and hence does
not have them.

Why Will It Be Cheap And Reliable?

This is a good question.  The Shuttle was supposed to be cheap and
reliable, and is neither.  However, there is reason for hope for SSTO.

The Shuttle's costs come mainly from the tremendous army of people
needed to inspect and refurbish it after each flight.  SSTO should get
by with many fewer.

The basic SSTO concept opens major possibilities for simple, quick
refurbishment.  With no discarded parts, nothing needs to be replaced.
With no separating parts, there is no need to re-assemble anything.
In principle, an SSTO vehicle should be able to "turn around" like
an airliner, with little more than refuelling.

Of course, this is easier said than done.  But there is no real reason
why SSTO should need much more.  Its electronics experience stresses
not much worse than those of an airliner -- certainly no worse than
those of a jet fighter.  Its structure and heatshield, designed to fly
many times, will have sufficient margins that they will not need
inspection and repair after every flight.  Most space-vehicle components
don't inherently need any more attention than airliner components.

The one obvious exception is the engines, which do indeed run at much
higher power levels than airliner engines.  But even here, airliner
principles can be applied:  the way to make engines last a long time
is to run them at less than 100% power.  SSTO engines have it easy in
one respect:  they only have to run for about ten minutes at the start
of the flight and two or three minutes at the end.

Still, the Shuttle engines certainly are not a shining example of low
maintenance and durability.  However, it's important to realize that
the Shuttle engines are not the only reusable rocket engines.  Most
liquid-fuel engines could be re-used, were it not that the launchers
carrying them are thrown away after every flight.  And the durability
record of these other engines -- although limited to test stands -- is
*much* better.  The RL-10 engine, which will be used in DC-X, is rated
to fire for over an hour, in one continuous burn or with up to ten
restarts, with *no* maintenance.  Several other engines have comparable
records.  Conservatively-designed engines are nowhere near as flakey
and troublesome as the Shuttle engines.

Here again, DC-X should soon supply some solid evidence.  Although its
engines and other systems are not the same ones that DC-Y would use,
they should be representative enough to demonstrate rapid, low-effort
refurbishment, and the DC-X program will try to do so.

Airliners typically operate at about three times fuel costs.  The fuel
cost for an SSTO vehicle would be a few dollars per pound of payload.
It may be a bit optimistic to try to apply airline experience to the
first version of a radically new vehicle.  However, even advanced
aircraft typically cost no more than ten times fuel cost.  Even if
SSTO comes nowhere near these predictions, it should still have no
trouble beating existing launchers, which cost several thousand dollars
per pound of payload.

We can look at this another way:  head counts.  Airlines typically have
about 150 people per aircraft, and most of those sell tickets or look
after passengers' needs.  Perhaps a better example is the SR-71, which
is like SSTO in that it was an advanced craft, pushing the frontiers
of technology, operated in quite small numbers.  Although it is hard
to get exact numbers because of secrecy, it appears that USAF SR-71
operations averaged perhaps one flight per day, using perhaps eight
flight-ready aircraft, with a total staff of about 400 people.  That's
50 per aircraft.  If SSTO can operate at such levels -- and there is
every reason to think it can -- it should have no trouble beating
existing launchers, which typically have several thousand people
involved in preparations for each and every launch.  (NASA's Shuttle
ground crew is variously estimated at 6,000-10,000 for a fleet of
four orbiters flying about eight flights a year.)

As for reliability, the crucial reason for thinking that SSTO will do
a lot better than existing launchers is simple:  testing.  It should
be feasible and affordable to test an SSTO launcher as thoroughly as
an aircraft.  This is *vastly* more thorough than any launcher.  The
F-15 fighter flew over 1,500 test flights before it was released for
military service.  No space launcher on Earth has flown that many
times, and the only one that even comes close is an old Soviet design.
It is no wonder that the Shuttle is somewhat unreliable, when it was
declared "operational" after a grand total of four test flights.
By aircraft standards, the Shuttle is still in early testing.  Some
expendable launchers have been declared operational after *two* tests.

Each and every SSTO vehicle can be tested many times before it carries
real payloads.  Moreover, since SSTO can survive most single failures,
it can be tested under extremes of flight conditions, like an aircraft.
For example, unlike Challenger, an SSTO vehicle would launch with
passengers and cargo in freezing temperatures only after multiple
test flights in such conditions.  There will always be surprises when a new
craft is flown in new conditions, but SSTO should encounter -- and
survive -- most of them in test flights.

Conclusion

Although there is reason for some uncertainty about the exact performance
of the first SSTO spacecraft, the basic approach being taken is sensible
and reasonable.  It should work.  The imminent test flights of the DC-X
test craft should resolve most remaining technical concerns.  Nobody can
be sure about costs and reliability until DC-Y is flying, but there is
reason to believe that SSTO should be much better than current launchers.
If the program is carried through to a flying DC-Y prototype in a timely
way, it really could revolutionize spaceflight.
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------188 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 19 Oct 92 17:19:30 GMT
From: Flammable Jammies <[e-mail]>
Subject: Info on book (including Nova rocket)
Newsgroups: sci.space

I have tried to email kr0u+andrew.cmu.edu, but I keep getting bounced.

You asked for the title of the book I am reading that referenced the Nova
rocket and is written from the perspective of the scientists, not the
astronauts.

Apollo, the race to the moon
by Charles A Murray
Catherine Bly Cox

Pg110 references the nova rocket.

It really is a good book so far, very interesting!

enjoy,
Thomas

[e-mail]

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

Date: 19 Oct 92 16:29:00 GMT
From: IGOR <[e-mail]>
Subject: Nuclear Power / FAQ
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Paul Dietz) writes...
>In article <[e-mail]> [e-mail] (IGOR) writes:
>
>> Nuclear power is to heat some fluid in order to get something out of
>> it.  How to heat it up ? put a lots of fissile materials all together
>> so that the neutron population increases exponentially, the heat comes
>> from the energy given away by the nucleus that is splitting ( fission
>> process).  In order for this reaction to occur more than once, one has
>> to reach the critical mass.. the main problem is to control this
>> neutron population, if it is not done one has a bomb...
>
>
>Am I the only one who feels nausea when this sort of cutsy, wrong
>answer is given?
>
>Perhaps folks should refrain from answering questions they don't
>know the answer to.

Damn right.

>
>"IGOR" should look up "radioisotope thermal generator", and
>"thermoelectric generator", when he has a chance.  I suppose
>electrons in a semiconductor could count as a fluid, but RTGs
>don't involve any fission chain reaction.


I did not talk about RTG's did I? And you're right they don't involve chain
reaction.
Perhaps you could throw up somewhere else sir, because It is my belief
 that the Sp100, the topaz or the nerva project are nuclear power related
projects. If you are not convinced of that why don't you come beginning of january
in albuquerque at the space nuclear power symposium, you might learn things.
As for the RTG's how can one compare decaying materials to fission controlled
 technology.....
Why so many people feel threatened when one does not give their answers as the
good one?

>
>There aren't *any* operating reactors in space right now, are
>there?

Well it even seems that you are contradicting yourself sir, anyway the
answer is NO on the american side,
 but looking at the urge the DoD wants to send one of the topaz
they own, it might be reality before the end of the century.

>
>    Paul F. Dietz
>    [e-mail]

as for RTG's they indeed do not need any critical mass, but then again this
was not the scope of the answer as our other intelligent readers have
understood.



Igor
Texas A&M University

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

Date: 19 Oct 92 12:03:43 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Pres Debate & military spending
Newsgroups: talk.politics.space,sci.space

In article <v=[e-mail]> [e-mail] (Michael V. Kent) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>Yeah, that's why I said Boeing might survive, they have a large backlog
>>of airliner orders. But once that's worked off, and with only three US
>>airlines still solvent new domestic orders are going to be scarce, they're
>>going to have to *really* hustle to *stay* in business at present levels of
>>employment, depending mostly on foreign flag sales, where bribery, a crime
>>under US law, is the normal mode of business.
>
>Boeing MIGHT survive?  Are we talking about the same Boeing here?  The one I
>refer to has a market share of 60% of the world's commercial transport orders.
>It is the nation's largest exporter.  It competes head to head against three
>of the largest governments in Europe and wins.  If only every American company
>did that good.

General Motors once dominated the world auto industry too, but look
at it now. Size alone isn't a guarrantee of survival when the market
changes. And loss of government business, and the expected declines
in domestic airline orders, *will* profoundly change the market.
Boeing has been smart so far, they have essentially already withdrawn
from the government market. And they have diversified beyond the
airliner market. I suspect that Boeing will survive quite nicely.
What I don't expect to survive is any relevance to future military
and space needs under the Boeing nameplate. That's not Boeing's
problem, but it may well be the US government's problem, and
consequently the US Taxpayer's problem when the world political
situation changes again, which it certainly will if history is
any guide.

Gary

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

Date: 19 Oct 92 06:19:28 GMT
From: "Frederick A. Ringwald" <[e-mail]>
Subject: Recognizing a Dyson sphere if you saw one
Newsgroups: sci.astro,sci.space

In article <[e-mail]>
[e-mail] (Frederick A. Ringwald) writes:

> A G dwarf with an infrared excess,

By the way, this might be taken as a naked T Tauri star, although it
might be thought strange if it's an old disk star with a slow rotation
rate. Interestingly, too, Kwang-Ping Cheng just published in the ApJ a
list of A stars with infrared excesses - which she attributes to
circumstellar disks, similar to those of Beta Pictoris (which has been
resolved in images as a disk), Fomalhaut, and Vega...

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

Date: 19 Oct 92 17:14:00 GMT
From: "Horowitz, Irwin Kenneth" <[e-mail]>
Subject: Recognizing a Dyson sphere if you saw one
Newsgroups: sci.astro,sci.space

In article <[e-mail]>, [e-mail] (Frederick A. Ringwald) writes...
>So, how can one recognize a Dyson sphere, among astronomical objects?
>Has anyone ever published anything serious about this?
>
A true Dyson sphere would have no optical counterpart, as all of the star's
radiant energy would be intercepted by the sphere itself.  What would be
observable (as mentioned in another post) is an infrared source of a few
hundred kelvin, with diameter of a few AU (you'd need the distance to the
source to measure this).  I'm sure that the IRAS database would not be useful
for this type of search, given the poor spatial resolution of that satellite.
SIRTF might do better.
-------------------------------------------------------------------------------
Irwin Horowitz                        |
Astronomy Department                  |"Whoever heard of a female astronomer?"
California Institute of Technology    |--Charlene Sinclair, "Dinosaurs"
[e-mail]                |
[e-mail]                 |
-------------------------------------------------------------------------------

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

Date: Mon, 19 Oct 92 17:07:08 EDT
From: Martin Gotz <[e-mail]>
Subject: SETI functional grammar

By using the overall galactic rotation, it is much simpler to define left and
right to any extraterrestrials. This definition works everywhere in our galaxy
and we don't have to explain any advanced quantum mechanics. The instructions
for the extraterrestrial would be like that (I hope that I have the direction
of the galactic rotation correctly in mind - if not, please correct these
instructions correspondingly):

  Cut our galaxy alongs its disk, perpendicular to its axis of rotation. Call
  that side of the galaxy, which faces the nearby Magellanic Clouds, the
  _southern_ side of the galaxy. The other side shall be the _northern_ side.
  If you look from outside the galaxy on its northern side, the galaxy
  rotates in a _right-handed_ way.
  Now put yourself into the galactic center, such that your top is in the
  northern part of the galaxy and your bottom in its southern part. Draw any
  straight line from the galactic center to its edge within the plane of the
  galactic disk. If you look along that line, the objects in the galaxy will
  pass that line from the _right_ to the _left_ due to the galactic rotation.

Please note, that a definition of left and right makes sense only if you have
defined top and bottom properly before. This can be done, e.g., by the
gravitational effects on the surface of the planet on which the
extraterrestrials live (any object falls from the _top_ to the _bottom_).

By the way, I would like to introduce myself. I study physics at Brown
University, Providence, RI at the moment. But in fact, I am from Germany. I
already studied at Tuebingen University (in south-west Germany) for three
years. I'm in a America as an exchange student.
-------------------------------------------------------------------------------
Martin Gotz
Box # 2169
Brown University
Providence, RI 02912
e-Mail: ST999012@BROWNVM

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

Date: 19 Oct 92 08:33:00 GMT
From: Tony Roby <[e-mail]>
Subject: Space Photos
Newsgroups: sci.space

I recently FTP'd some data files from sseop.jsc.nasa.gov, which are apparently
digitised versions of various photos taken with the Hasselblads on the space
shuttle.  The data files are in DUA2:[STS45.PHOTOS] and each file is 3MB long.
The files contain three chunks (red, green & blue) of 1024x1024 pixels.
I converted the data to a Targa file and have been quite disappointed at the
image quality considering the amount of data in the file.  Has anynone
else used this site and, if so, can you comment on the quality of the photos ?
I'm not convinced that my conversion program is totally accurate and I was
expecting some dramatic pictures.  Also, there are various high quality .GIFs
around of space scenes - where do they come from ?  Is there a NASA source ?

Tony

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

Date: 19 Oct 92 17:12:09 GMT
From: Jim Bowery <[e-mail]>
Subject: Sundrive
Newsgroups: sci.space

[e-mail] (Ian Stirling) writes:

> Re the idea of putting a reflective sphere with a window in round a star
> and using as a drive.
>
> Pity, it looked such a nice concept, maybe the numbers are better for
> small, hot stars?  How could you focus the beam to make it hit a
> interstellar probe?
> Any problems with my math?

No.  But reaction mass from the star should be used instead of photons.

--
INTERNET:  [e-mail] (Jim Bowery)
UUCP:   ...!ryptyde!netlink!jim
NetLink Online Communications * Public Access in San Diego, CA [phone]

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

Date: 18 Oct 92 20:24:50 GMT
From: Bruce Watson <[e-mail]>
Subject: V-2's launched at Russia (was Re: V-2 anniversary)
Newsgroups: sci.space,soc.history

In article <[e-mail]| [e-mail] (Elliott Kleinrock) writes:
|In article <[e-mail]| [e-mail] (Bruce Watson) writes:
||Successful V-2 combat launches (From 'The Rocket Team', Ordway and Sharpe,
|1979)
|
||UK
||   London     1359
||   Ipswich       1
||   Norwich      43
|
||Belgium
||   Antwerp    1610
||   Liege        86
||   Brussels   (See Other)
|
||France
||   Paris        19
|
||Other
||   Continental 137 (including 11 at Remagen, the town whose bridge was
||                    captured before it could be blown up, Tournai, Hasselt
||                    Maastricht (been in the news lately), Lille, Arras, Mons,
||                    Cambrai, St. Quentin, and Tourning.)

|
||Total         3225
|
|
|Where any V-2's launched at Russia?
|    - Elliott

Not enough range, 260 miles was the maximum. I don't why none were fired
eastward at the advancing Russian Army.

--
Bruce Watson (wats@scicom)  Tumbra, Zorkovick; Sparkula zoom krackadomando.

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

End of Space Digest Volume 15 : Issue 327
------------------------------