Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_4/V16NO419.TXT

Internet Message Format | 1993-07-13 | 34KB

Date: Mon,  5 Apr 93 05:00:03
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #419
To: Space Digest Readers
Precedence: bulk


Space Digest                Mon,  5 Apr 93       Volume 16 : Issue 419

Today's Topics:
                  Alaska Pipeline and Space Station!
                         Atlas rocket questio
                        Atlas rocket question
                   DC-X: Vehicle Nears Flight Test
                       DCX "Roll out" (2 msgs)
                Gemini 8 (was Re: Artificial Gravity)
           John Sheehan & Russian Space Mission to Seattle
                    Machine intelligence (2 msgs)
                        Mexican Space Program?
          Oregon L-5 meeting: 2 pm, Sat. April 10, old OMSI
                    Ottawa Astronomy Info Needed!
                    Portable Small Ground Station?
                        Prefab Space Station?
                         pushing the envelope
                       Space Research Spin Off
                             Tommy's Oil

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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----------------------------------------------------------------------

Date: Sun, 4 Apr 1993 19:06:55 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Alaska Pipeline and Space Station!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>Sure they could, but consider that a commercial concern has to retire
>capital expenditures, plus interest, has to cover operating costs, and
>make a profit. If the government builds it for their own use, they don't
>have to make a profit, nor do they have to borrow the bulk of the money
>to pay for it, so interest charges are less.

And this, ladies and gentlemen, is why the US has a multi-trillion $$ debt.

No Gary, the governemnt does indeed pay interest.

>The sticking point is that the government has to sign a firm rental
>agreement in advance of construction that guarantees a certain amount
>of rent for a specified period once construction is complete. And that
>contract has to have penalty clauses sufficient to keep the landlord
>solvent if the government reneges on the contract. This has been the
>sticking point. Most government contracts have a termination clause


Not any more. Last years NASA Authorization bill allows NASA to negotiate
termination liability.

  allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------73 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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

Date: 04 Apr 93  09:49:02
From: [e-mail]
Subject: Atlas rocket questio
Newsgroups: sci.space

HS>The key thing to remember is that the Atlas is not a representative
HS>vehicle. :-)  With the balloon tanks and near-complete absence of any
HS>structural members, the engines are *most* of the mass of a stage usin
HS>Atlas technology.
HS>
HS>This is what you get when you really lean on rocket engineers to make
HS>a lightweight rocket stage, instead of having them build a heavy-duty
HS>tank with rocket engines attached.  Which is why Atlas made it into
HS>orbit on 1.5 stages in 1958, a performance unequalled to this day.


What would it take in materials technology to make an Atlas into a SSTO
with return to Earth capability; i.e., where could weight be saved?


___ WinQwk 2.0b#0

--- Maximus 2.01wb

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

Date: Sun, 4 Apr 1993 23:48:16 GMT
From: Henry Spencer <[e-mail]>
Subject: Atlas rocket question
Newsgroups: sci.space

In article <1plcg3$[e-mail]> [e-mail] (Pat) writes:
>|This is what you get when you really lean on rocket engineers to make
>|a lightweight rocket stage...
>
>Of course, it's fragile like heck.

Not really.  One of the standard tricks of the GD people was to show
skeptics a pressurized section of Atlas skin -- stainless steel about
the thickness of a dime -- hand them a sledgehammer and tell them to
do their worst.  (The thing you had to know was that you should stand
well back, because the hammer would bounce much higher than the skeptic
expected and he'd usually lose control of it.)  It wasn't possible to
leave a mark on it, never mind damage it.

The thing that it did have to be guarded against was pressure loss,
either through compressor failure or through being punctured by something
sharp-edged.

>I think one got wrecked when it got bumped with
>a scaffold.

Nope, slashed open by a sharp edge on a motorized work platform.

>It may make sense just for  proving SSTO,  but for reliable
>performance I think we need  better performing materials
>and heavier duty aircraft like rockets.

For a reusable rocket, something more fault-tolerant is in order.  For
an expendable, I don't think it's an unreasonable design approach.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Mon, 5 Apr 1993 00:05:18 GMT
From: Henry Spencer <[e-mail]>
Subject: DC-X: Vehicle Nears Flight Test
Newsgroups: sci.space

In article <2736@snap> [e-mail]-mrc (Paul Johnson) writes:
>This bit interests me.  How much automatic control is there?  Is it
>purely autonomous or is there some degree of ground control?

The "stick-and-rudder man" is always the onboard computer.  The computer
normally gets its orders from a stored program, but they can be overridden
from the ground.

>How is
>the transition from aerodynamic flight (if thats what it is) to hover
>accomplished?  This is the really new part...

It's also one of the tricky parts.  There are four different ideas, and
DC-X will probably end up trying all of them.  (This is from talking to
Mitch Burnside Clapp, who's one of the DC-X test pilots, at Making Orbit.)

(1) Pop a drogue chute from the nose, light the engines once the thing
    stabilizes base-first.  Simple and reliable.  Heavy shock loads
    on an area of structure that doesn't otherwise carry major loads.
    Needs a door in the "hot" part of the structure, a door whose
    operation is mission-critical.

(2) Switch off pitch stability -- the DC is aerodynamically unstable at
    subsonic speeds -- wait for it to flip, and catch it at 180
    degrees, then light engines.  A bit scary.

(3) Light the engines and use thrust vectoring to push the tail around.
    Probably the preferred method in the long run.  Tricky because
    of the fuel-feed plumbing:  the fuel will start off in the tops
    of the tanks, then slop down to the bottoms during the flip.
    Keeping the engines properly fed will be complicated.

(4) Build up speed in a dive, then pull up hard (losing a lot of speed,
    this thing's L/D is not that great) until it's headed up and
    the vertical velocity drops to zero, at which point it starts
    to fall tail-first.  Light engines.  Also a bit scary, and you
    probably don't have enough altitude left to try again.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 4 Apr 93 16:35:15 GMT
From: Gregory Hamlin <[e-mail]>
Subject: DCX "Roll out"
Newsgroups: sci.space

So, does anyone have any info about the DCX "roll out" on april 3?
Was is shown on any news programs?  Did anyone take any pictures which
could be scanned and posted/ftp'd somewhere as GIF/JPEG files? :)

Greg Hamlin
[e-mail]

P.S Anyone else notice the similarity between DCX and the rocket Bugs
Bunny rode to Mars? (landing gear extend, and rocket lands tail first)

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

Date: 4 Apr 1993 21:06:38 GMT
From: Diaspar Virtual Reality Network <[e-mail]>
Subject: DCX "Roll out"
Newsgroups: sci.space

   I attended both the press briefing and the rollout and will be
putting more information here as I get a chance to write it up.
The good news is I got lots of stereoscopic video "footage" and
will be converting a number of the best shots to .gifs and it
will include shots of not just the vehicle but of some of the
people at the press conference. I'll have .gifs that are both
normal and stereo pairs (left/right)

As a quick summary of the rollout I will mention a few things.
First, the weather was perfect: clear, sunny, high 70's to low
80's. The press conference before the rollout was not unduly long,
McDonnell Douglas made a major effort to make people welcome and
to handle the crowd (est 1500) that was there. One can tell
the turnout was larger at the last minute than expected since
they ran out of hot dogs (but thankfully not soft drinks as it
was hot). Col. Worden brought down the house at one time during the
press conference when asked a question about how much money the
Air Force had available for projects like these. He replied "I
didn't make colonel by telling my contractors how much money I have
available to spend."

The rollout ceremony was pretty straighforward - a number
of not-too-long speeches (including one each from a republican
and democrate Congressman) and then the vehicle was pulled out of the
The DC-X, as advertised, is about 41 feet tall, round at the
top, squarish at the bottom, has rather large landing gear. Was
really something to see paretns bringing their kids up and touching it
and looking in the access hatches which were open (but covered with
plexiglass).

The concept of quick turnaround from idea to a finisahed unit
and the concept of aircraft-style flight operations is appealing to
me. It kind of hit home when people were allowed to touch the
thing. I've touched more aircraft in my life that I can count, but
this is the first time I've touched a space ship.

D
D
D
D
D
D
DX
hanger by an interesting little tractor/carrier. The DC

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

Date: Sun, 4 Apr 1993 23:33:40 GMT
From: Henry Spencer <[e-mail]>
Subject: Gemini 8 (was Re: Artificial Gravity)
Newsgroups: sci.space

In article <1pa5n2$[e-mail]> [e-mail] (Pat) writes:
>>Armstrong ... also had to eject from an LLRV when rehearsing a lunar
>>landing.)
>
>From my understanding,  The LLRV had some sort of delay in the
>control mechanism.  Armstrong found that out the hard way.

Nope.  See the excellent overview article on the LLRV/LLTV program in the
Dec 1992 issue of Spaceflight.  Despite what you sometimes hear, the things
were not that hard to fly, according to the test pilots who checked them
out first.  Armstrong ejected from LLRV-1 after helium pressure in the
peroxide tanks (yes, another peroxide-fuelled rocket!) fell too low and
he lost his control thrusters as a result.  Some months later, Joe Algranti
ejected from LLTV-1 when a sharp gust of wind sent it out of control, and
a couple of years later, Stuart Present had to eject from LLTV-2 after an
electrical failure.  LLRV-2 and LLTV-3 survived to retire after Apollo 17
crew training concluded; LLRV-2 is at Dryden, while LLTV-3 spent some
years on display at Marshall and is now at Johnson.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 4 Apr 93 13:57:27 GMT
From: "P. Douglas Reeder" <[e-mail]>
Subject: John Sheehan & Russian Space Mission to Seattle
Newsgroups: sci.space

[ The following article first appeared in StarSeed, the newsletter of
the Oregon L-5 Society, and is reprinted by permission of the editor. ]


Russian Space Mission to Seattle
by John Sheehan

  I've covered many exciting and curious events as a videographer. Most
began, as this one did, with a last minute phone call. Bob Walsh &
Associates, the master promoters who brought Seattle the "Goodwill Games",
asked me if I would like to videotape the recovery of a Russian satellite. As
part of "Europe America Space Flight 500", the even
t was being billed as "the final chapter ending the Cold War."
  And so, after checking my equipment and renting extra batteries, I drove to
the airstrip at Grays Harbor. Eight other journalists and I were  shuttled by
helicopter 25 miles off the Washington coast to a mysterious Russian ship. My
partner in the helicopter that day was Tim Crosby, a photojournalist from
Edmonds who had traveled to Siberia for Outside Magazine. Once in the air the
dark shape of a large ship loomed on the horizon. Before we
 could get our bearings we were deposited on a rolling deck.
  The "Marshal Krylov" is a 680 foot missile tracking ship, until recently
top secret and off-limits to foreigners. We were welcomed aboard by Commander
Alexander Rosskazov on behalf of Captain Vadim Yevgenievich Shardyn. Soon we
were taken on a short tour of the ship which included a theater with a
balcony, a steam bath ("bahnya" in Russian), and a ships museum featuring
models of space vehicles such as "Buran", the Russian shuttle craft.
  Our first night at sea was spent sailing into the teeth of a fierce wind
storm. Gales of 60 knot winds and 40 foot seas tossed the huge ship about
like a cork. Luckily, I had taken my Dramamine so I wasn't too uncomfortable.
Still it took me most of the next day to acquire my "sea-legs" and stop
bouncing off of bulkheads. As I recovered, the other American observers and I
covered the routine of the
Russian sailors as they went about their work.
  Aside from the obvious language barriers, I found the Russian sailors a lot
like the seamen that I served with in the U.S. Coast Guard. Many are very
young (as I was) and see naval service as a way to travel abroad and see
world. They were curious about America and told me that their only
impressions of The United States, other than the bleak news stories fed to
them under the previous regimes, came from the violent American action films
which are sadly a
s popular in Russia as they are here
  On Sunday morning we gathered in the impressive "Capsule Descent
Communications Center" and watch a 40 foot screen as the re-entry began. Soon
however, we realized that the data on the screen was being updated by hand.
The telemetry with the capsule and tracking was actually being relayed to the
ship from Moscow via radio telephone. The actual recovery itself ,th
ough, was a daring bit of seamanship.
  As the ship bucked in heavy seas, the deck crew struggled to swing a boom
with a steel cable net over the side, all the time battling howling winds.
With great effort they succeeded to scoop the 3 ton satellite out of the
water and hoist it onto deck. Once secured in its cradle, the payload was
checked by grim technicians from Samara, where the satellite was built. This
Siberian city, once secret and officially off limits, is devoted entirely to
aerospace manufact
uring.
  With their mission completed and the visit to Seattle ahead of them, the
crew relaxed and celebrated with a talent show in the theater. The show
featured a rock band, a guitar strumming balladeer, and the triangular
"ballalyka" accompanied by a button accordion. The next morning, as we sailed
through the straights and into Puget Sound, many of the sailors pointed to
the Olympic Mountains and commented on how much the geography reminded them
of Kamchatka peninsula, where the "Krylov" is based. But as the tall
buildings of Seattle loomed up before them, they seemed to realize that they
truly were visiting an American city of heroic proportions. Many of the men
came out on deck and took pictures of th
eir comrades at the rails with the Space Needle over their shoulders.
  My videotape of the recovery appeared on several major networks including
CNN. Tim Crosby's photos were featured in Newsweek and the German magazine
Der Stern.
  One of my friends, upon hearing of my adventure, remarked "Oh gosh, we only
see things like that on TV!" I had to remind her that some one like me has to
be there with a camera before it can be shown.

--
Doug Reeder                              Internet: [e-mail]
Div, Grad & Curl                         USENET:   ...!tektronix!reed!reeder
programming & derivative work
I am actively seeking scientific programming contracts.

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

Date: Sun, 4 Apr 93 15:40:17 EDT
From: John Roberts <[e-mail]>
Subject: Machine intelligence

>From: [e-mail] (fred j mccall 575-3539)
>Newsgroups: sci.space,talk.politics.space
>Subject: Re: Luddites in space
>Date: 2 Apr 93 16:37:34 GMT
>Organization: Texas Instruments Inc

[On the topic of advanced automation for unmanned spacecraft.]

>You might also want to note that Herman Rubin is right.  Machines
>*can't* be intelligent.  The question, of course, is just how much
>intelligence is required for a given task...

>[e-mail] - I don't speak for others and they don't speak for me.

The question of current and near-term capabilities of machines is a valid
one. But I'd like to know your reasoning for the first statement, that
machines are inherently capable of displaying intelligent behavior.

This has been discussed in Scientific American, and I didn't think much of
some of the arguments presented there. Some people argue that intelligence
is a human concept, so by definition, only humans can be intelligent.
I'd say it will be embarrassing if we ever encounter an alien civilization,
and have to break the news to them that they're not really intelligent -
they just *think* they are. :-)

Some of the other arguments given:
 - Religious reasons. You have to have a soul to be intelligent. (Can't
   really be argued one way or another on scientific grounds.)
 - Computational speed. The brain is faster than current computers, which
   is especially noticeable in speech recognition and image recognition.
   (An invalid argument - speed of operation has nothing to do with the
   abstract concept of intelligence. Storage capacity isn't an issue either -
   computer memory can be made as large as necessary.)
 - Only living cells can embody intelligence. (The New Age equivalent of
   the religious argument.)
 - Only certain kinds of hardware can perform the operations of intelligence
   (flip-flops, or neural nets, or organic compounds regulating propagation
   of sodium-potassium imbalances). (Which strikes me as a considerable leap
   of faith in itself. More below.)

The thing to remember about computational machines is that other than
computational speed (which I don't accept as a valid criterion for posession
of abstract intelligence), an outside observer can't distinguish a correct
*emulation* from a hardware implementation. Consider, for example, neural
nets, which are patterned after the behavior of human neurons. Some people
think that computers made with neural nets could be made intelligent, while
conventional computers can not. But if you can completely describe the
behavior of a neural net component, then you can write a program that runs
on a conventional computer which causes it to behave like a neural net
(though perhaps slower). Even random or chaotic behavior can be modeled
if you can describe it properly and can come up with adequate random number
generators, etc.

In general, *any* computational or data-manipulating task can be emulated
by a general-purpose computer with an appropriate program and sufficient
memory (as shown by Mr. Turing). The only way a computer *can't* be made
to work in a way that to an outside observer is indistinguishable from
what we consider intelligent is if the operations of intelligence are in
some way inherently indescribable. There are people who claim that's the
case, but I'd really like to know how they're *sure*.

(By the way - the questions of how intelligent we can make machines now,
or how intelligent we can currently make machines that are small enough
to fit on a spacecraft, or how intelligent we *want* machines to be
are separate issues from the potential ability to make them intelligent.)

So - in what way do you feel that machines can't be intelligent?

John Roberts
[e-mail]

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

Date: Sun, 04 Apr 1993 22:28:35 GMT
From: nathan wallace <[e-mail]>
Subject: Machine intelligence
Newsgroups: sci.space

As a low-level grunt in the neural-nets/ai field, I thought I might add a comment or
two here.

(Asbestos Underwear ---ON!)

"Intelligence" in this context usually means the ability to duplicate *all* human behavior
which impacts cognitive activity. This includes reasoning, both formal and "common-
sense", and a property sometimes called "intentionality", which is a way of describing
the ability to make personal decisions *not* deterministically predictable from inputs.
Any entity, be it a computer or a creature from Tau Ceti IV, which displays these abilities
is very likely going to be considered "intelligent" by the current cog-sci community.

(An interesting side note on this whole business is that the imputation of intentionality
to anyone but ourselves runs into the problem described by Descartes, namely that
we have to more or less take it on faith that other people who look like us and act like
us have mental states like us, even though we can't directly percieve those states in
others!)

If this seems to be rapidly getting bogged down in verbiage, you're right! Trying to
grapple with these concepts keeps us ai types in business at the moment, and far
more time is spent splitting rabbits in the literature than revealing profound new
insights into intelligence and so forth!

At the moment, we have hit dead ends on getting machines to either have common-
sense reasoning, or display intentionality. Until somebody can break through these
two barriers, ai and the concept of "machine intelligence" is pretty much at a standstill.

Except for neural nets....

The above was about "strong" or  "classical" ai, which uses things like lisp and tries to
find clever algorithms to implement on binary hardware. ann's (artificial neural nets)
can run rings around the best classical ai solutions in many fields, and actually have
some people hoping to break through the common-sense reasoning barrier with them,
by finding a new way to let a net "learn" commonsense properties rather than have to
explicitly list them to it.

Intentionality, which might also be called "self-awareness", though, is a bit farther off.
This is where most religious arguments seem to apply. Strong proponents say that
the right formal system instantiated on the right hardware will develop intentionality.
Strong opponents say otherwise, for reasons listed in a previous post plus others. Us
nn guys tend to stay out of this argument, I've noticed.

Another important point about ann's: note that "a" on the front. Our current implementation
of "artificial" neural nets have about as much in common with the neurons of the brain
in humans as an abacus has with a workstation; both compute, but there are many fundamental
differences in the method and abilities. Current ann's are far more like specialized statistical
analysis programs than real neuron simulations. (My personal contribution is to try and
increase our understanding of the real neurons so we can make anns' more like them!)

For a definitely not-strong-ai perspective on the matter, one might try reading a book by
Hans Jonas entitled "The Phenomenon of Life". It has some interesting historical perspectives
on the whole ai field/debate.

(Asbestos Underwear---OFF!)

Just my $0.02 worth, as a space enthusiast with some cs background. Any opinions here are
strictly mine and not my college's, my advisor's, or my mother's!
---
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: Sun, 4 Apr 1993 09:03:39 GMT
From: Nick Szabo <[e-mail]>
Subject: Mexican Space Program?
Newsgroups: sci.space,talk.politics.space

[e-mail] (Gary Coffman) writes:

>The US government is not in the business of exporting
>US jobs with taxpayer funds, nor is it in the business of exporting
>the technological industrial base on which it's security depends.
>All the cries to "Buy Russian", or "Move Boeing to Tijuana" neglect
>these issues.

Quite the opposite -- the cries to keep everything
in the U.S. just like it is ossify the U.S. industry, prevent it
from growing.  The $billions we spend right now on labor-intensive
manufacturing could be shifted towards retraining
and high-skill, high-wage jobs like engineering if we let the
free market operate.  Right now we have gross overproduction and
duplication of function at incredibly high costs.  Having over
ten launchers on the planet to handle a demand for 100 launches per
year is completely ridiculous by commercial aerospace standards.

In a free market a glut causes lower prices,
which in turn would make space industry more affordable and expand
the market.  The ecconomic level might be 500 launches per year
by 4 or 5 launchers in the 2000 timeframe.  That's five times the
number of launches for half the tooling, or up to a factor of 10
reduction in launch costs just from removing protectionist barriers.
More benefits come from sharing technology and freeing U.S. engineers to
design the next generation launcher, and, even more importantly,
the next generation of payloads to open up new markets made
possible by lower launch costs and greater engineering talent
dedicated to the payloads.  DBS and cellsats need only about
a factor of 2-4 launch cost reduction to go from marginal to
>$10 billion per year industries, and some kinds of space
manufacturing (eg electrophoresis, protein crystal growing, &
other biotech stuff) might also reach the economical range.

But I have to admit that the argument you make is the easy
way out for those working for government contractors, and thus
there is a large political pressure to maintain protectionism.
Alas, if that prevails we can expect a continuation of our
system of stifling space bureaucracy, and we can forget about
ideas to lower launch costs or expand space industry; trying to
compete with tax collectors is a losing proposition (as
AT&T in the 1960s, AMROC and Gerry O'Neill in the 1980s, and
many others have found to their chagrin).


--
Nick Szabo                     [e-mail]

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

Date: 4 Apr 93 13:52:52 GMT
From: "P. Douglas Reeder" <[e-mail]>
Subject: Oregon L-5 meeting: 2 pm, Sat. April 10, old OMSI
Newsgroups: sci.space

Our April 10 meeting is our quarterly Space Update at the OMSI Annex
(old OMSI building), for which we have two special presentations.
Videographer John Sheehan was aboard the Russian recovery ship for a
good-will satellite drop offshore from Seattle and is producing a
video documentary of the project.  He will tell us about his
experiences and hopefully have some video footage to show us.  Seattle
Lunar Group Studies' Hugh Kelso and associates will be here to present
some of their work in preparing for lunar settlement.  This
well-respected group is a spin-off of the now-defunct Seattle NSS
chapters.




--
Doug Reeder                              Internet: [e-mail]
Div, Grad & Curl                         USENET:   ...!tektronix!reed!reeder
programming & derivative work
I am actively seeking scientific programming contracts.

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

Date: Sun, 4 Apr 1993 13:45:23 GMT
From: Ray Moyneur <[e-mail]>
Subject: Ottawa Astronomy Info Needed!
Newsgroups: sci.space

    I am looking for information on any type of Amateur Astronomy meetings
that might take place in the Ottawa/hull area.

thanks,


--
           +---------------------------------------------------+
          /                                                     \
         (       Ray Moyneur   --  [e-mail]     )
          \_____________________________________________________/

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

Date: Sun, 4 Apr 1993 23:37:33 GMT
From: Henry Spencer <[e-mail]>
Subject: Portable Small Ground Station?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>How difficult would it be to set up your own ground station?

Ground station for *what*?  At one extreme, some of the amateur-radio
satellites have sometimes been reachable with hand-held radios.  At the
other, nothing you can do in your back yard will let you listen in on
Galileo.  Please be more specific.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Sun, 4 Apr 1993 23:46:56 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Prefab Space Station?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>Some of the problems with Shuttle C are political, but there are
>other issues as well. The sticking point is the cost of SSMEs.
>They're too expensive to throw away on an expendible launch.

This is not an issue for two reasons.

First of all, Shuttle is so expensive that a Shuttle-C using brand new
SSME's would still be much cheaper than Shuttle. Even doubling the cost
of Shuttle C would still result in multi-billion $$ savings for Fred
construction.

Secondly, this puts the cart before the horse. The issue is heavy
lift, not Shuttle C. Both Martin Marrettia and McDonnell douglas have
proposed Titan and Delta variants easilly developed for far less than
Shuttle. We could build and operate BOTH these options for Freedom
assembly and save billions.

  Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------73 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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

Date: Sun, 4 Apr 1993 10:00:30 GMT
From: David Pugh <[e-mail]>
Subject: pushing the envelope
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Elijah Millgram) writes:
|> A friend of mine and I were wondering where the expression "pushing
|> the envelope" comes from.  Anyone out there know?

Aircraft and the like have a "flight envelope" which describes the conditions in
which the plane can fly safely. A trivial example is the stall and "never exceed"
speeds for an airplane: flying outside that speed range is a bad idea (though
not always immediately fatal). The flight envelope is determined by the simple
approach of having someone demonstrate that the plane can safely fly under the
given conditions. "Pushing the envelope" is what happens when someone
intentionally flys outside the flight envelope (going faster, higher, with a
heavier payload, at a larger angle of attack, etc.) to prove that the plane
is safe under the new conditions. If the plane is "safe" under the new conditions
(nothing bent, control response was good, etc.), then the flight envelope is
extended to include the new conditions.

--
... He was determined to discover the        David Pugh
underlying logic behind the universe.        ...!seismo!cmucs!dep
    Which was going to be hard, because
there wasn't one.    _Mort_,  Terry Pratchett

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

Date: 4 Apr 1993 20:31:10 -0400
From: Pat <[e-mail]>
Subject: Space Research Spin Off
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Question is can someone give me 10 examples of direct NASA/Space related
>research that helped humanity in general? It will be interesting to see..


TANG :-)
Mylar I think.
I think they also pushed  Hi Tech Composites for airframes.
Look at Fly by Wire.

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

Date: Sun, 4 Apr 1993 08:56:04 GMT
From: Nick Szabo <[e-mail]>
Subject: Tommy's Oil
Newsgroups: sci.space,sci.chem.engr

>On Date: 30 Mar 93 04:45:31 GMT, William Reiken <[e-mail]>
>writes:
>/    A Question:  Has oil been found anywhere eles in our Solar System
>/        in the raw form that we dig it up in here on earth?

Methane, ethane, and several other hydrocarbons have been seen in
varying abundance (<1% to 5% for methane) in comets.  If you want
to get rich in 2020, design a system to extract the methane from
the water & ammonia ice and the gravel/muck of comets, perhaps
by doing "distillation" by creating a large gas/plasma interface
(cf. comet tail dynamics).  Bonus points for separating out the
ammonia, or coming up with a water/ammonia/methane mix that can be
kept frozen and used as a thermal propellant (no need to haul tank
from earth).


--
Nick Szabo                     [e-mail]

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End of Space Digest Volume 16 : Issue 419
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